In the field of industry, heavy metal- and bromine-based flame retardants and so forth in various materials and products have been indicated to be hazardous to humans and the environment, and the regulation of harmful substances has been growing around the world. For instance, in Europe, the “Directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment (RoHS Directive)” prohibits the use of parts containing more than 100 ppm cadmium (Cd) or more than 1000 ppm lead (Pb), mercury (Hg), certain bromine-based flame retardants (polybrominated biphenyls (PBB) or polybrominated biphenyl ethers (PBDE)), or hexavalent chromium (Cr (VI)). Accordingly, it is absolutely essential that manufacturers of electrical and electronic equipment confirm that the various parts they make do not contain more than the regulated amounts of hazardous substances.
In general, the content of a hazardous substance such as an environmental hazardous substance is assayed or measured by performing quantitative analysis. In this quantitative analysis, fluorescent X-ray analysis is utilized because it makes compositional analysis possible on the order of a few tens of parts per million, and allows non-destructive measurement. Quantitative analysis featuring fluorescent X-ray analysis is used to assay contents in many other fields as well (see Patent Documents 1 and 2, for example).
With the above-mentioned conventional assay methods, quantitative analysis is performed on all parts that are supposed to be assayed, regardless of whether or not any environmental hazardous substances or other hazardous substances are actually contained, so detailed analysis ends up being performed even on parts containing no hazardous substances, which wastes time in the processing step. For example, it takes about 12 minutes to perform quantitative analysis of five elements for a single part. Consequently, it is desirable to eliminate unnecessary processing and shorten the processing time, particularly in processing steps involving a large quantity of parts. Also, since the analysis results are outputted as numerical values, the operator has to visually confirm the values and make a decision about the content, which imposes a significant burden on the operator.
Furthermore, if the sample is a composite part composed of a plurality of materials, determining by X-ray analysis which of the parts in the composite part contains the hazardous substance requires that the composite part be taken apart to its constituent parts composed of single materials prior to analysis. Therefore, the time it takes for disassembly and the burden on the operator are major obstacles.
Patent Document 1: Japanese published unexamined patent Application No. H7-49317
Patent Document 2: Japanese published unexamined patent Application No. H7-63707